diff --git a/HISTORY.rst b/HISTORY.rst
index 30df34be..e0bf1ad0 100644
--- a/HISTORY.rst
+++ b/HISTORY.rst
@@ -12,7 +12,8 @@ PlatformIO Core 5
 ~~~~~~~~~~~~~~~~~~
 
 - Allowed to override a default library builder via a new ``builder`` field in a ``build`` group of `library.json <https://docs.platformio.org/page/librarymanager/config.html#build>`__ manifest (`issue #3957 <https://github.com/platformio/platformio-core/issues/3957>`_)
-- Handle "test" folder as a part of CLion project (`issue #4005 <https://github.com/platformio/platformio-core/issues/4005>`_)
+- Handle the "test" folder as a part of CLion project (`issue #4005 <https://github.com/platformio/platformio-core/issues/4005>`_)
+- Improved handling of a library root based on "Conan" or "CMake" build systems (`issue #3887 <https://github.com/platformio/platformio-core/issues/3887>`_)
 - Fixed a "KeyError: Invalid board option 'build.cpu'" when using a precompiled library with a board that does not have a CPU field in the manifest (`issue #4056 <https://github.com/platformio/platformio-core/issues/4056>`_)
 - Fixed a "FileExist" error when the `platformio ci <https://docs.platformio.org/en/latest/userguide/cmd_ci.html>`__ command is used in pair with the ``--keep-build-dir`` option (`issue #4011 <https://github.com/platformio/platformio-core/issues/4011>`_)
 - Fixed an issue with draft values of C++ language standards that broke static analysis via Cppcheck (`issue #3944 <https://github.com/platformio/platformio-core/issues/3944>`_)
diff --git a/platformio/builder/tools/piolib.py b/platformio/builder/tools/piolib.py
index 9b6d9642..eb92f352 100644
--- a/platformio/builder/tools/piolib.py
+++ b/platformio/builder/tools/piolib.py
@@ -184,11 +184,11 @@ class LibBuilderBase(object):
 
     @property
     def include_dir(self):
-        if not all(
-            os.path.isdir(os.path.join(self.path, d)) for d in ("include", "src")
-        ):
-            return None
-        return os.path.join(self.path, "include")
+        return (
+            os.path.join(self.path, "include")
+            if os.path.isdir(os.path.join(self.path, "include"))
+            else None
+        )
 
     @property
     def src_dir(self):
@@ -501,6 +501,14 @@ class ArduinoLibBuilder(LibBuilderBase):
             return {}
         return ManifestParserFactory.new_from_file(manifest_path).as_dict()
 
+    @property
+    def include_dir(self):
+        if not all(
+            os.path.isdir(os.path.join(self.path, d)) for d in ("include", "src")
+        ):
+            return None
+        return os.path.join(self.path, "include")
+
     def get_include_dirs(self):
         include_dirs = LibBuilderBase.get_include_dirs(self)
         if os.path.isdir(os.path.join(self.path, "src")):
diff --git a/platformio/package/manager/library.py b/platformio/package/manager/library.py
index 03960306..95f2db3f 100644
--- a/platformio/package/manager/library.py
+++ b/platformio/package/manager/library.py
@@ -61,6 +61,12 @@ class LibraryPackageManager(BasePackageManager):  # pylint: disable=too-many-anc
     @staticmethod
     def find_library_root(path):
         for root, dirs, files in os.walk(path):
+            # check if Conan-based library
+            if os.path.isfile(os.path.join(root, "conanfile.py")):
+                return root
+            # check if CMake-based library
+            if os.path.isfile(os.path.join(root, "CMakeLists.txt")):
+                return root
             if not files and len(dirs) == 1:
                 continue
             for fname in files: